This invention relates to rotary dryer drums, and in particular to a rotary dryer drum in which the drum may radially expand and in which heat transfer to the wheels and bearings of the drum is reduced.
Rotary drum dryers are used to dry a variety of products and to thermally treat foundry sand. When heating the products or sand, the heat from the product or sand is transferred to the drum, causing the drum to heat up and expand. Typically, the rotary drum is mounted on a base and includes wheels and bearings which allow to the drum to rotate on the base. When the drum does heat up, such heat is transmitted to the wheels and bearings. Such heat can be detrimental to the wheels and bearings.
The drum operates by tumbling the products through the dryer. As the products are tumbled, they create localized shocks or forces which are passed to the wheels and bearings. These localized forces can also damage the wheels and bearings.